What structures are the spindle fibers attached to that help pull the paired chromosomes?

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.

The cluster of developing cells from conception until birth is called an

The bacteria inside a tube worm would be analogous to what organism in the ocean ecosystem near the waters surface? a. photosynthetic algae b. shrimp c. clown fish d. parasitic lamprey